Method and apparatus for web based storage on-demand

ABSTRACT

The operation efficiency of a large scale distributed computing system across the world wide web is critical to any enterprise or ISP or ASP operation due to a larger number of various different computing units involved. The introduction of a service pool construction protocol can help enterprise, ISP and ASP to achieve a high degree of automation for creating and managing different service pools in respect to the needs for storage capacity, in the large scale distributed computing system.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application is a continuation of U.S. patent application Ser. No. 15/214,798 filed on Jul. 20, 2016 and now a U.S. Pat. No. 9,787,780 which itself is a continuation of U.S. patent application Ser. No. 14/513,444 filed on Oct. 14, 2014 and now a U.S. Pat. No. 9,602,600, which in turn itself is a continuation of U.S. patent application Ser. No. 13/663,710 filed on Oct. 30, 2012, now a U.S. Pat. No. 8,909,976 which itself is a division of U.S. patent application Ser. No. 12/013,813 filed on Jan. 14, 2008 and now a U.S. Pat. No. 8,639,788, which in turn itself is a divisional application of U.S. patent application Ser. No. 10/713,905 filed on Aug. 12, 2002, and now a U.S. Pat. No. 7,379,990. All above applications and patents are herein incorporated by references in their entireties for all purpose.

FIELD OF THE INVENTION

The present invention generally relates to computer communications network. More specifically, the present invention relates to web based data storage systems.

BACKGROUND OF THE INVENTION

Today's corporate IT professionals typically face many challenges to handle the ever increasing information and data. To handle large amount of data, many organizations are required to expand their storage capacity by employing managed storage systems locally in order to maintaining their normal business operating. A conventional approach is to use IP based network attached storage (“NAS”), which effectively provides data storage and services for end users. Moreover, at the enterprise level, the majority storage systems are directly attached or connected to server(s) or host(s) as shown in FIG. 7. These server(s) and/or host(s) are typically access to raw block data devices through conventional communication connection media, such as traditional IDE, SCSI, Fibre Channel, or Ethernet.

The server, which is directly attached to a storage system as illustrated in FIG. 7 typically has many drawbacks, which are described as following:

A typical conventional storage system is only capable of handling 4 TB (terabytes) of data, which is usually not good enough to meet the demands for a typical enterprise storage system;

The most of servers, which are directly attached to storage systems, have problems for further expanding their storage capacity. Therefore, an organization may require to purchase new servers in order to increase storage capacity;

The storage being attached to a server can only be accessed by the attached server and can not be shared by other servers even if the server has larger amount of storage spaces not being used;

Each attached storage system has to be managed separately and this is a nightmare for IT professionals;

With the attached storage system, the backup/restore has to go through the data network, this will tax or reduce the network performance;

A typical SCSI connection only allows a 12-meter distance for data accessing with 15 storage devices. Similarly, Fibre Channel is limited to 10 kilometers communication distance. Distance limitation effectively prevents them from being the best choice for disaster recovery of the storage system; and

The Fiber Channel based storage system cannot handle well for the interoperability. Also, Fibre Channel based storage system is expensive to build and to maintain.

FIG. 8 shows a conventional type of virtual SAN, which is in-band controlled and accessed with which the data path from hosts 1 to the SAN units 4 going through virtual SAN control management station 2. It is not efficient in term of accessing the data by the hosts because the virtual SAN control management station can easily be a performance bottleneck. Similarly, the scalability of this type of virtual SAN is poor.

SUMMARY

With rapid development of high speed communication technology, the problems mentioned above can be solved by an IP based out-band accessed distributed virtual SAN infrastructure illustrated in FIG. 1 of this invention. The IP base virtual SAN provides a method of grouping multiple IP SAN units to a storage system with huge capacity to meet the demanding for increasing storage capacity for keeping business running normally. With this invention, each host 1 can directly access IP based SAN units 4 without going through control management station (“control system”) 3. The IP based out-band accessed distributed virtual SAN infrastructure actually represents an example of central controlled distributed scalable virtual machine system (CCDSVM) illustrated in FIG. 9. Wherein, each system units actually is a SAN unit 4, specifically is an IP based SAN unit.

With this invention by referring to the FIG. 1 and FIG. 6, in one embodiment, each SAN unit 4 can be accessed by one or more hosts 1 and each host 1 can access one or more SAN units 4 as illustrated in FIG. 6. In addition, the storage accessing goes directly through communication link 2 between the hosts 1 and SAN units 4 without involvement of the control management station 3. Further, for increasing storage capacity, SAN unit 4 can be dynamically added at any time without interrupting normal data accessing of the existing SAN units 4 from the hosts 1. Further, all SAN units are centrally controlled, monitored, and managed by a control management station 3 through a management console 10 of a console system 14. The control management station 3 may also accept storage volume (or partition) requests from each host 1, and assign the matched volumes (or partitions) on the SAN units 4 to the requested hosts. Thereafter, each host 1 could directly access the right volumes (or partitions) on the assigned SAN units without going through the control management station 3 again.

This invention will become understood with reference to the following description, claims, and accompanying figures.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be understood more fully from the detailed description given below and from the accompanying drawings of various embodiments of the invention, which, however, should not be taken to limit the invention to the specific embodiments, but are for explanation and understanding only. Specially, in the drawings, like elements are designated by like reference numbers.

FIG. 1 illustrates a distributed virtual storage area of network (“SAN”) infrastructure in accordance with one embodiment of the present invention;

FIG. 2 illustrates actual components of Distributed Virtual SAN in accordance with one embodiment of the present invention;

FIG. 3 illustrates Virtual SAN automatic configuration protocol in accordance with one embodiment of the present invention;

FIG. 4 illustrates a packet format used for message communication in a Virtual SAN automatic configuration protocol in accordance with one embodiment of the present invention;

FIG. 5 illustrates an example of storage volume information of an IP SAN Unit in accordance with one embodiment of the present invention;

FIG. 6 illustrates a hypothetical example of storage volume requests and assignment in accordance with one embodiment of the present invention;

FIG. 7 is a conventional Direct Attached Storage System;

FIG. 8 is an in-bound accessed virtual storage system;

FIG. 9 illustrates a simplified diagram of a central controlled distributed scalable virtual machine system in accordance with one embodiment of the present invention; and

FIG. 10 illustrates a simplified diagram of disaster recovery scheme of a distributed virtual san infrastructure in accordance with one embodiment of the present invention.

DETAILED DESCRIPTION

The following terms are used through out this patent application to describe the present invention. A central controlled distributed scalable virtual machine (“CCDSVM”) system in one embodiment allows a control management system to control a group of computing systems and to provide distributed services to client systems across the Intranet, Internet, and/or LAN environment. Storage media includes various types such as magnetic hard disk drives, solid state disk drives, optical storage drive, and memory card. Storage connection and control media may include controller such as IDE, SCSI, Fibre optical, Ethernet, and USB controller, or wireless media, and/or other related cable. Each controller for storage media such as Raid, IDE, or SCSI controller may control multiple storage media on a computing system. Storage system includes one or more storage media (devices), storage connection media, and storage media controllers. Storage system also contains related software modules for delivering storage services.

Storage area network (“SAN”) is a storage system that is capable of providing block data services to various computer devices (hosts) through storage connection media, such as Fibre-optical cable, Ethernet cable or others by deploying Internet Protocol (“IP”) based or non-IP based protocol. The non-IP based protocol, in one example, includes Fibre-Channel protocol. IP SAN uses IP based protocols to provide storage raw block data services. All discussions of the SAN in this invention are within the scope of a model of central controlled distributed scalable virtual machine (“CCDSVM”).

DNS stands for domain name service for the Internet network. DNS is an Internet software infrastructure and is capable of identifying network addresses and name for computing systems. For example, the network addresses may be used by a computing system to communicate with the peer systems. A Simple Network Management Protocol (“SNMP”) is a standard Internet protocol for managing computing system on a network. A SNMP trap is a user datagram protocol (“UDP”) packet, which may be sent by a SNMP daemon on a SNMP agent system to a SNMP network management station via network links.

FIG. 1 shows an example of a simplified block diagram of IP based out-band accessed distributed virtual SAN infrastructure. The distributed virtual SAN infrastructure includes multiple hosts 1, network infrastructures 2, a control management station 3, a virtual storage pool 11 having multiple IP SAN units 4, and a management console 10. In one embodiment, each of the hosts 1 contains service software modules 9. The service software modules 9 are configured to communicate with a control management software module 7 of the control management station 3 for obtaining information of a specific one of the IP SAN units 4, and performing tasks distributed from the control management system 3, e.g. upon tasks submitted from a management console 10. The service software modules 9 also communicate with service software modules 6 of each of the IP SAN units 4 for access block data service provided by the each of the SAN units 4. For example, each of the hosts 1 can create a local file system or create a local database by using block data service delivered through storage volumes in the virtual SAN. The service software modules 9 can be coded or implemented with suitable programming languages such as C, C++, Java or others. The service software modules 9 may also use suitable protocols such as IP based or non-IP based protocols.

The host 1, in one embodiment, could be a server, a desktop, a laptop PC, or a communication system or device, which needs to access block data storage. The spare host 12 represents a part of recovery scheme that could be implemented in a CCDSVM environment.

Network infrastructure 2 comprises many kinds of links such as data link. The network infrastructure 2 could be a storage backbone of an enterprise, a department LAN, a corporate intranet, an Internet infrastructure or others such as WAN (wide area network). In one embodiment, network infrastructure 2 includes switches, routers, gateways, cables (Ethernet, optical Fibre), wireless communication media, or others. The network infrastructure 2 provides data path between the hosts 1, the distribute control management station 3, and the SAN Units 4. The network infrastructure 2 also includes software infrastructure such as DNS or DHCP for facilitating computing systems on the network to identifying a target addresses of a another computing system for sending or receiving data within a network domain or in a cross-domain network environment.

It should be noted that DNS and/or other Internet address identification mechanism may be used when a message or data stream is sent from a system A to a system B across a network, such as via communication link of the network infrastructure.

The control management station 3 includes distributing control management software modules 7 and console support software modules 8. To support web-based console, it requires the web server software 15. The distribute control management software modules 7 communicate with service modules 6 of each of the IP SAN units 4 to retrieve storage information for constructing a virtual SAN storage service pool 11. The communication between the distributed control management software modules 7 and the service modules 6 of each of the IP SAN units 4 is further configured to monitor each of the IP SAN units, and to perform various system operations, such as storage configuration and partitioning. The control management software modules 7 also communicate with service software modules 9 of each of the hosts 1 for distributing storage volumes to each of the hosts 1. The distribute control management software modules 7 can be implemented with suitable programming languages such as C, C++, Java, XML, and others. The communication protocols between control management station 3 and IP SAN units 4 could be suitable IP based protocols. The communication between the control management station 3 and hosts 1 can be suitable IP base or non-IP based protocols.

The console support software modules 8 employ inter-process communication mechanism to obtain information relating to each of the IP SAN units (4) from the distributed control management software modules 7. The console support software modules 8 further provide the obtained information to web server software 15 through the inter-process communication mechanism. The console support software modules 8 can be implemented with suitable programming languages such as C, C++, Java, XML.

The web server software 15 communicates with the management console software 10 on the console host 14 through web protocol such as HTTP for providing the obtained information, e.g. via a web user interface (“UI”), for centralized storage management for the entire distributed virtual SAN infrastructure across a network. The web server software 15 could be commercially available software or other proprietary software.

To simplify foregoing discussion, the communication path mentioned above will be simply referred to as the console support software modules 8 communicate (send/receive data) with the management console 10 of the console host 14 without further mentioning the role and function of web server software 15 of the control management station 3.

In addition, to support non-web based console, the web server software 15 on the control management station 3 is often not required. In this case, the console support software modules 8 could communicate with the management console software 10 with a suitable protocol other than a web protocol such as HTTP.

The virtual storage pool 11 includes multiple IP SAN units 4, wherein each of the IP SAN units further includes service modules 6 and is configured with storage media, storage communications and control media. The storage media of each of the IP SAN units 4 is configured to have one or more logical volumes. Each storage volume, in one embodiment, is further partitioned into several partitions as shown in FIG. 5. The service software modules 6 are configured to communicate with distribute control management station 3 for providing storage information and for performing storage operations distributed from the control management station 3 such as for partitioning storage volumes. The service software modules 6, in another embodiment, are further configured to communicate with service software modules 9 of each of the hosts 1 for providing block data services to the hosts 1. The service software modules 6 can be implemented by suitable programming languages such as C, C++, Java, and they may employ suitable IP based communication protocols for data transfer.

In one embodiment, the control management station 3 organizes the IP SAN units 4 to form the virtual storage pool 11. The virtual storage pool can be represented by a storage information list, where each entry on the list comprises information for a SAN unit, such as SAN Unit's name and IP address, status such as online or down, storage media information such as disk drives or raid, storage configuration information such as number of storage volumes/partition, allocation and capacity size information. A spare IP SAN unit 13 represents a part of recovery scheme used in the centrally controlled distributed scalable virtual machine environment.

A Fibre channel to IP gateway 5 is a component that is configured to provide translation between Fibre Channel based protocol and IP based protocol so that a Fibre Channel based SAN unit will appear as if a IP based SAN unit to the rest of the world (FIG. 1).

Fibre channel SAN unit is similar to an IP SAN unit 4 except it uses Fibre Channel storage controller, which uses Fibre Channel protocol to communicate with other parties over a network. In addition, a Fibre Channel SAN unit appears as an IP based SAN unit to the distributed virtual SAN once it connects to the Fibre Channel to IP gateway 5. Therefore, to simplify the foregoing discussion, a fibre channel SAN unit will be treated similarly as an IP SAN unit in all of following discussion without additional comments.

The management console 10 on the console host 14, which has been described in pending patent application of “Concurrent Web Based Multi-Task Support for Control Management System” of application Ser. No. 10/713,904 filed on Aug. 6, 2002 by the same author and is incorporated herein by reference in its entirety. The management console 10 could be a commercially available web browser or a proprietary web browser. A web browser 10 is able to communicate with web server software 15 on the control management station 3 through a web protocol such as HTTP. The Web browser 10 could be implemented by suitable programming languages such as C, C++, Java, XML. In addition, the management console software module 10 could be a networked software module other than a web browser software. In this case, a suitable network protocols can be used instead of using web protocol such as HTTP.

To simplify the foregoing discussion, the communication path between the management console 10 of the console host 14 and the console support software modules 8 of the control management station 3 will not further mention the role or function of the web server software module 15 in this invention.

From a management console 10, multiple concurrent system operations and tasks can be performed by user for the entire distributed virtual SAN infrastructure. There are may be one or more management consoles of the distributed virtual SAN infrastructure on the network infrastructure.

FIG. 2 illustrates a portion of FIG. 1 relating to an actual virtual SAN. The multiple SAN units 4 form a virtual storage pool 11. The virtual storage pool 11 may contain information of each of the IP SAN units' IP address, the storage volumes and their sizes configured on each storage device.

FIG. 3 shows a protocol for a virtual SAN automatic configuration as well as for shutting down a SAN unit 4 in the virtual storage pool 11 of the virtual SAN. The packet format used with this protocol is described in FIG. 4.

FIG. 4 shows the message format, which is used by “Virtual SAN Automatic Configuration Protocol” for sending and receiving a packet. The packet contains both source and designated address information for sender and receiver; therefore, the packet may be transmitted cross the Internet without Internet address identification mechanism such as the DNS, or DHCP if both the source and designated addresses are known.

FIG. 5 illustrates storage layout in an IP SAN unit 4, wherein the storage layout may be further configured into multiple volumes and each volume may be further partitioned into multiple partitions. Each volume refers to a logical storage unit in this discussion and it might contain one or multiple pieces of storage spaces from multiple storage hardware media.

FIG. 6 is a simplified and a portion of FIG. 1, which shows a hypothetical example of how hosts are configured to access the storage volume of IP SAN units. Where the IP SAN units 4 are a portion of the virtual storage pool 11 and each host is substantially the same as presented in FIG. 1.

FIG. 8 is a block diagram illustrating an In-Band Accessed Virtual SAN. FIG. 8 shows another type of virtual SAN, where, the actual storage data path from hosts to IP SAN units has to go through control management station.

FIG. 9 is a Simplified diagram of central controlled distributed scalable virtual machine (“CCDSVM”). With this invention, the systems in a CCDSVM can be flexibly configured into multiple different types of service pools according to their functionalities. For example, multiple IP SAN units 4 can form a virtual SAN storage pool. The hosts of the CCDSVM could form other service pools to provide services other than storage services such as video services, security monitor services, web service, file service, database service and other services provided on the world wide web (or across a network) by using storages in the virtual SAN infrastructure.

Fig. 10 is a simplified diagram of disaster recovery scheme of the distributed virtual SAN infrastructure, which includes one virtual storage pool 11 of multiple IP SAN units 4 and one service pool of multiple hosts 1. For example, host 1 (1) accesses IP SAN units 4 (1) and (2) while host 1 (3) accesses IP SAN units 4 (4) and (5). Also, IP SAN units 4 (1) and (2) are mirrored so that they may kept the similar copy of data for host 1 (1). The same to be true for IP SAN units 4 (4) and (5) with host 1 (3). In addition, IP SAN unit 4 (3) may be a spare unit and the host 1 (2) could be a spare host for providing fault replacement in case a fault occurred.

FIG. 1 shows a simplified diagram of a distributed virtual SAN infrastructure according to the present invention. With the distributed virtual SAN infrastructure, the distributed virtual SAN storage pool 11 comprises one or more SAN units 4, which may be further connected to a distribute control management station 3. The SAN units 4 can be accessed by one or more hosts 1 via the network infrastructure 2. The entire distributed virtual SAN infrastructure can be operated through a management console 10 for centralized operation.

The virtual storage volume pool 11 of the distributed virtual SAN infrastructure can be initiated and updated when each of the IP SAN units 4 is booted up and brought to online. The virtual storage volume pool 11, in one embodiment, is updated when at least one of IP SAN units is powered down or removed from the web environment. FIG. 3 shows the distributed Virtual SAN Automatic Configuration Protocol, which leads to the success of constructing the virtual storage pool 11 of the distributed virtual SAN infrastructure according to this invention. The following steps are for automatic building the storage volume pool 11 of the distributed virtual SAN based on the protocol illustrated in FIG. 3. The protocol described bellow could be IP based protocol such as SNMP, or a much simple UDP based protocol as illustrated in FIG. 4, or other suitable protocols.

When one of the IP SAN units 4 such as unit (n) brought up online, SAN service modules 6 of the one of IP SAN units 4 sends out a “SAN unit (n) startup” packet (message), as illustrated in FIG. 4, to the distribute control management station 3. The “SAN unit (n) startup” packet could be a simple user defined UDP packet indicating a storage system labeled with an number “n” just being powered up. The message carried by the packet could also be a SNMP trap of cold start packet, or link-up packet if the communication link of the IP SAN unit 4 was previously down, or other short packet/message of a suitable IP protocol.

When the distribute control management modules 7 of the distribute control management station 3 receives the IP SAN unit (n)'s message, it stores the IP SAN unit (n)'s information, such as storing into a storage information list for the virtual storage pool 11.

After storing information of the IP SAN unit, the control management modules 7 on the distribute control management station 3 sends back a “need SAN unit (n)'s storage info” packet to the IP SAN unit (n) 4.

When the SAN service modules 6 of the IP SAN unit (n) 4 receive the packet of “need SAN unit (n)'s storage info”, the SAN service modules 6 obtain the storage information on the IP SAN units (n) 4, which may include the number of storage volumes, each storage volume's starting address (logical block address, LBA), length (size), and the end address (logical block address, LBA). The SAN service modules 6 then send back a packet of “unit (n) storage info”, which may include all information obtained, to the control management station 3.

After receiving the “unit (n) storage info” packet from the IP SAN unit (n) 4, the distribute control management modules 7 of on the distribute control management station 3 update the stored information of the virtual storage pool 11 by including corresponding storage information of the IP SAN unit (n) obtained from the packet.

When an IP SAN unit (n) is shutting down, the service module 6 of the IP SAN unit (n) 4 sends a “Unit (n) shutdown” message to the distribute control management station 3. This shutdown message could be an SNMP trap of link down, or a simple UDP packet as illustrated in FIG. 4 with a message type of system down, or other short packet based on some other protocols.

After receiving of the “unit (n) shutdown” packet from the IP SAN unit (n) 4, the distribute control management modules 7 on the distribute control management station 3 update the stored information of the virtual storage pool 11 for the IP SAN unit (n) 4, for example, updating and marking the status of the IP SAN unit number (n) as down in an entry of the storage information list. In addition, other information may be also updated, for example, updating the total size of the virtual storage capacity as well as updating client hosts storage volume allocation information.

After one or more IP SAN units 4 are brought online, the control management station 3 obtains the stored information relating to storage volumes and network for every IP SAN unit 4 in the virtual storage pool 11. Therefore, the control management station 3 can control the entire virtual SAN and is able to distributed storage volumes to hosts 1 based on request in several steps in respect to the FIG. 6:

First, a host 1 numbered as (1) sends a request to the control management station 3 for requesting a storage space, such as for a 80 GB (gigabyte) of storage. Second, the control management station 3 stores information of the host 1 (1) and searches for availability of the 80 GB of storage volume from the virtual storage pool 11. The control management station 3, for example, finds an 80 GB available storage volume labeled as volume number (2) in an IP SAN unit 4 labeled as (M). Third, the control management station 3 sends the requested information of the host 1 (1) to the IP SAN unit 4 (M), where the requested information includes the IP address of the host 1 (1) and the requested storage size. The control management station 3 also sends the storage volume (2) information relating to the IP SAN unit 4 (M) to the host 1 (1), where the storage volume (2) information includes the IP address of the IP SAN unit 4 (M), the storage volume number and the size, the storage volume's starting and ending logical block address (LBA). Therefore, all parties of three, namely the control management station 3 and the host 1 (1) and the IP SAN unit 4 (M) are synchronized for keeping the same mapping of the storage volume assignment information. Fourth, once the host 1 (1) and the IP SAN unit 4 (M) get each other's information, the host 1 (1) can directly and independently access the storage volume (2) on the IP SAN unit 4 (M) immediately without going through the control management system 3, and the IP SAN unit 4 (M) in one embodiment is further configured to perform security checking in light of permission for storage accessing by the host 1 (1).

Alternatively, the above described steps for distributing storage volume may also be semi-automatically setup with assisting of operations performed via the management console 10. For example, an administrator via the management console 10 of a console host 14 could manually setup the storage volume (2) of the IP SAN unit 4 (M) to be exclusively accessed by the host 1 (1) as long as the administrator acknowledges that the host 1 (1) needs such size of storage volume. The administrator can also manually setup the host 1 (1) with all information needed to access the storage volume (2) of the IP SAN unit 4 (M). Finally, the host 1 (1) can access to the storage volume (2) of the IP SAN unit 4 (M) directly without going through the control management station 3.

The present invention also discloses a mechanism of dynamically expanding storage capacity. After the distributed virtual SAN storage pool 11 is built, each of the hosts 1 will be able to access the storage volumes on one or more of the IP SAN units 4 in the pool 11 directly without further involvement of the control management station 3. This will allow the virtual storage pool 11 of the distributed virtual SAN infrastructure to continue expanding its capacity by adding one or more SAN storage units 4, without affecting the hosts 1 to continue accessing the storage volumes on the assigned IP SAN units 4 in the virtual storage pool 11. This guarantees that the capacity of the distributed virtual SAN storage pool 11 can be dynamically expanded without interrupting normal storage operations and accessing of the entire distributed virtual SAN storage pool 11.

The present invention further discloses a technique of system scalability. Once the distributed virtual SAN storage pool 11 is constructed, each host 1 can access one or more IP SAN units 4 in the virtual storage pool 11 of the distributed virtual SAN infrastructure whenever the host 1 sends a request. For example, the host 1 (1) illustrated in FIG. 6 can access three IP SAN units that numbered as SAN unit 4 (1), unit (2), and unit (M) after the host 1 (1) requests for storage volumes, subsequently, the control management station 3 grants each of the requests. This effectively provides scalable storage system for the hosts 1 (1) within distributed virtual SAN infrastructure of this invention. Further, the distributed virtual SAN infrastructure provides far better scalability than the in-band accessed virtual SAN as illustrated in FIG. 8, wherein the scalability of in-band accessed virtual SAN were severely limited by a bottlenecked control management station.

The present invention also discloses a method of storage sharing mechanism. Once the distributed virtual SAN storage pool 11 is constructed, each IP SAN unit 4 in the virtual storage pool of distributed virtual SAN infrastructure may be hold multiple storage volumes in the form of block data, which can be accessed by one or more hosts 1. Therefore, this allows multiple hosts (1) to share an IP SAN unit 4 by granting and assigning each of the hosts to exclusively access one of the storage volumes on the IP SAN unit 4. The FIG. 6 demonstrates such a storage sharing, where the IP SAN unit 4 number as (2) has three volumes, which named as volume (1), volume (2), and volume (3). The block data service modules 6 of the IP SAN unit 4 (2) allows a volume (1) to be accessed exclusively by a host 1 (1) while volume (2) to be accessed exclusively by a host 1 (2).

With in-band accessed traditional SAN as illustrated in FIG. 8, the control management station could be a performance bottleneck. With distributed virtual SAN of this invention, each host 1 can directly and independently access IP SAN units 4. Therefore, the performance of storage accessing by each host will not be affected by the control system, yet can match the performance of directly attached storage system as illustrated in FIG. 7 when the high speed network connecting media is deployed in the distributed virtual SAN infrastructure.

The present invention also illustrates a method of a centralized management of distributed virtual SAN infrastructure for all IP SAN units 4, control management system 2 and hosts 1 within the infrastructure. As discussed before, the storage management console 10 on a console host 14 can communicate with the console support software module 8 of on a control management station 3 for obtaining information relating to all IP SAN units 4 and hosts 1 from the control management modules 7 of the control management station 3. Therefore, the management console 10, e.g. through a web user interface (“UI”), can provide centralized management functionality for the entire distributed virtual SAN storage pool 11, for the hosts 1, and for the control management station itself 3. With multiple concurrent tasks supported by the console support software modules 8 of the control management station 3, the storage management console 10 can efficiently provide full range of system operations and tasks. In addition, multiple tasks and operations can be run concurrently throughout the entire distributed virtual SAN and the hosts 1. These management tasks include storage configuration, storage volume allocation (assignment) for hosts or de-allocation for hosts, storage partitioning and repartitioning, storage backup or restore, fault handling, and monitoring status of storage, network, and other resource usage and activities.

This invention also discloses multi-level security management mechanism for provide security protection for the entire IP virtual SAN infrastructure. At control management system 3 level, an authentication process can be enforced for users e.g. validating user name and password to determine if a user is allowed to access management console 10, and also validating if a user is permitted to perform a specific task or operation for IP SAN unit 4 or host. At IP SAN units 4 and host level, a validation can be made if a particular host is permitted to access storage volume on a specific IP SAN unit 4.

In one embodiment, the present invention discloses a process of disaster recovery mechanism. The use of DNS or an IP address identification mechanism can help this distributed virtual SAN infrastructure to overcome the geometric (region) limitation, and works well in a cross network domain environment or in a single network domain environment. Therefore, the IP SAN units 4 or hosts 1 as well as a control management station 3 could be anywhere on the corporate Intranet, department LAN, WAN or Internet. As a result, the present invention can be used for an emergency or a disaster recovery plan because the distributed virtual SAN infrastructure can be implemented with a range beyond 100 miles as oppose to the traditional 10-kilometer limitation.

In addition, the disaster recovery plan of distributed virtual SAN infrastructure can be flexibly implemented as showing in FIG. 10. With this recovery plan, the host 1 numbered as (1) or (3) can continue to operate even if one of mirrored IP SAN units 4 serving the host (1) or host (3) is failed. Also, a spare IP SAN unit 4 can be used to quickly replace the failed IP SAN unit 4 whenever there is a need. On the other hand, the hosts 1 illustrated in FIG. 10 also can be organized into a service pool for providing special services, such as distributing video services, distributed database pool for database service, distributed security monitor services, and all other services provided on the network or the World Wide Web. Therefore, whenever the host 1 (1) or (3) has failed, a spare host 1 (2) can quickly take over the host 1 (1)'s or the host 1 (3)'s assigned IP SAN storage and replace the host 1 (1) or the host 1 (3) to continue providing services to the end user computing devices.

It should be noted that the storage of a IP SAN unit 4 can be shared and accessed by multiple hosts. To scale a virtual storage, a host may be assigned to access multiple volumes of storage capacities from multiple IP SAN units. In one embodiment, the storage access goes directly through communication link between hosts 1 and SAN units 4, which means that it is an out-band access. An advantage of using the present invention is that it has better performance and scalability than that in-band accessed virtual SAN. Furthermore, the present invention allows the virtual storage pool 11 to expand dynamically through adding more IP SAN units into the pool 11 without interrupting systems operation.

The distributed virtual SAN infrastructure can be managed and monitored from a centralized console 10. Also, the IP based distributed virtual SAN infrastructure is a new type of central controlled distributed scalable virtual machine (CCDSVM). The software modules implemented in the IP based distributed virtual SAN infrastructure are formed a web based virtual operating system model. Furthermore, the methods and principles of automatically constructing the IP based distributed virtual storage pool can be applied to non-IP base SAN and to many other type of distributed virtual machine, e.g. to automatically build different type of application service pools for hosts delivering various on-demand service and to provide ability of group based management for hosts and the virtual storage pool. The present invention can also apply to various data distribution services within the CCDSVM infrastructure. To effectively apply the method and principle of automatic constructing virtual storage pool of this invention to other types of application service pools served by hosts, each host need to be configured to provide a unique service, such as configured for a host providing video service. In addition the “storage information” in the protocol for automatic constructing storage service pool needs to be replaced by specific service information, for example replaced by “video file information” for video service. Thus a specific application service pool can be automatically created to deliver the specific service to client system. In addition, the different type of application service pools will have similar advantages as the storage service pool does, such as dynamical capacity expanding, scalability, performance, disaster recoverability, security, centralized management and support service on-demand. 

The invention claimed is:
 1. A method of expanding storage capacity for a computing system, the method comprising: creating a first storage volume pool for a need to increase storage capacity of the computing system, wherein the first storage volume pool comprises a plurality of storage servers, is created by executing a storage pool construction protocol between a first control device and each of the storage servers and is represented by a storage information list; connecting the first storage volume pool through a network infrastructure to a first host pool of a plurality of host devices in the computing system; receiving, by the first control device through a first communication link, a first request from a first one of the host devices for a need of increasing storage capacity of the first one of the host devices; identifying a first storage volume in a first one of the storage servers in the first storage volume pool to satisfy the need of storage capacity of the first one of the host devices; synchronizing a mapping between the first one of the storage servers, the first one of the host devices, and the first control device, the mapping includes information of assigning the first storage volume to the first one of the host devices; instructing the first one of the host devices, through a second communication link, directly accessing the first storage volume independent of the first control device.
 2. The method of claim 1, wherein each of the storage servers comprises a plurality of storage devices being partitioned into one or more storage volumes, where each storage volume is a logical storage unit spanning across one or more of the storage devices and comprising information of size, starting and ending logical block address (LBA) of the storage volume, and can be exclusively assigned to a specific one of the host devices.
 3. The method of claim 2, wherein each entry on the storage information list comprises information of a storage server that includes associated name, IP address, status, storage device configuration, and storage volume partitioning and assignment/mapping information.
 4. The method of claim 3, where the mapping for storage assignment comprises names and network addresses for the first one of the storage servers and the first one of the host devices, and the address and size information of the first storage volume.
 5. The method of claim 1, wherein the network infrastructure comprises communication links in an across corporate intranet, the Internet, wide area network (WAN) and/or local area network (LAN) environment.
 6. The method of claim 1, wherein the first control device controls, through executing said storage pool construction protocol, automatically forming the first storage volume pool with maximum number of the storage servers according to the capacity of the first control device.
 7. The method of claim 1, wherein the first host pool is automatically formed through executing a service pool constructing protocol between a control device and each of the host devices across a network in the network infrastructure.
 8. The method of claim 7, wherein each of the host devices is configured operable to utilize one or more storage volumes in the first storage volume pool for delivering a specific service to a plurality of user devices, wherein the storage volumes are physically residing in one or multiple storage servers in the first storage volume pool.
 9. The method of claim 1, further comprising: receiving a second request for a need of increasing storage capacity from the first or a second one of the host devices; identifying whether a storage server having a second storage volume in the first storage volume pool available to satisfy the need for storage capacity; and assigning exclusively the second storage volume to the requested host device upon a success from the identifying, wherein the second storage volume residing in the first or the second one of the storage servers; and updating the storage information list to reflect the assignment of the second storage volume.
 10. The method of claim 3, wherein the storage pool construction protocol executed by the first control device comprises steps of: a) receiving a packet sent automatically from the first one of the storage servers upon which being brought online to inform the first control device that the first one of the storage servers is going online; b) storing identification information of the first one of the storage servers, obtained via the packet, into the storage information list for the first storage volume pool, and c) sending an enquiry packet back to the first one of the storage servers for requesting storage information of the first one of the storage servers for supporting storage volume distribution and storage management; d) receiving from the first one of the storage servers a response packet comprising the required storage information, including information of at least one storage volume configured in the first one of the storage servers, according to the enquiry; and e) updating the stored information for the first storage volume pool with the storage information of the first one of the storage servers obtained through the response packet; f) following the step a) to step e) for adding each additional storage server into the first storage volume pool.
 11. The method of claim 9, wherein the updating of the first storage volume pool further comprises: updating the capacity size of the first storage volume pool to reflect the changing status of a storage server in the pool upon occurring of disconnection or shutdown or power off of the storage server, and allocation (assigning) or de-allocation of a storage volume thereof.
 12. The method of claim 1, further comprising: creating a second storage volume pool for a need to increase storage capacity of the computing system, wherein the second storage volume pool is accessible to the first host pool or a second host pool of a plurality of host devices in the computing system.
 13. The method of claim 11, further comprising: determining the storage capacity of the first storage volume pool and the storage volume assignments (allocations) thereof for identifying a need for creating a second storage volume pool.
 14. A computing system comprising: a first storage volume pool, comprising a plurality of storage servers and represented by a storage information list, each of the storage servers configured with one or more storage volumes; at least a first host pool comprising a plurality of host devices, each host device being configured operable to utilize one or more storage volumes in the first storage volume pool for delivering service to a plurality of user devices; and a network infrastructure configured for connecting the first storage volume pool to the first host pool; wherein the first storage volume pool is created for a need to increase storage capacity of the host devices by executing a storage pool construction protocol between a first control device and each of the storage servers; wherein the first control device controls storage allocation of the first storage volume pool, comprising: receiving, through a first communication link, a first request from a first one of the host devices for a need of increasing storage capacity thereof; identifying a first storage volume in the first storage volume pool available for the need of storage capacity, wherein the first storage volume resides in a first one of the storage servers; synchronizing a mapping between the first one of the storage servers, the first one of the host devices, and the first control device, the mapping including information of assigning the first storage volume to the first one of the host devices; authorizing the first one of the host devices, through a second communication link, directly accessing the first storage volume independent of the first control device according to the mapping.
 15. The computing system of claim 14, wherein each of the storage servers comprises a plurality of storage devices being partitioned into one or more storage volumes, where each storage volume is a logical storage unit spanning across one or more of the storage devices and comprising information of size, starting and ending logical block address (LBA) of the storage volume, and can be exclusively assigned to one of the host devices.
 16. The computing system of claim 15, wherein each entry on the storage information list comprises information of a storage server that includes associated name, IP address, status, storage device configuration, and storage volume partitioning and assignment/mapping information.
 17. The computing system of claim 14, wherein the first control device controls, through executing said storage pool construction protocol, automatically forming the first storage volume pool with maximum number of the storage servers according to the capacity of the first control device.
 18. The computing system of claim 14, wherein the first control device further controls: receiving a second request, for a need of increasing storage capacity, from the first or a second one of the host devices; identifying whether a storage servers having a second storage volume in the first storage volume pool available to satisfy the need for storage capacity; and assigning the second storage volume exclusively to the requested host device upon a success from said indentifying, wherein the second storage volume residing in the first or a second one of the storage servers; and updating the storage information list to reflect the assignment of the second storage volume.
 19. The computing system of claim 18, wherein the updating of the first storage volume pool further comprises: updating the capacity size of the first storage volume pool to reflect the changing status of a storage server in the pool upon occurring of disconnection or shutdown or power off a storage server therein, or allocation (assigning) or de-allocation of a storage volume thereof.
 20. The computing system of claim 14, further comprising: creating a second storage volume pool for a need to increase storage capacity of the computing system, wherein the second storage volume pool is accessible to the first host pool or a second host pool of a plurality of host devices in the computing system. 